JP3680644B2

JP3680644B2 - Rectifier circuit

Info

Publication number: JP3680644B2
Application number: JP18860399A
Authority: JP
Inventors: 康浩大熊; 和明三野
Original assignee: Fuji Electric Systems Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 1999-07-02
Filing date: 1999-07-02
Publication date: 2005-08-10
Anticipated expiration: 2019-07-02
Also published as: JP2001025257A

Description

【０００１】
【発明の属する技術分野】
この発明は、三相交流電圧を任意の直流電圧に変換し、この直流電圧を負荷に供給する整流回路に関する。
【０００２】
【従来の技術】
図５は、この種の整流回路の第１の従来例を示す回路構成図であり、１は三相交流電源、２は三相ブリッジ構成に結線されたダイオード整流器、３は平滑用の電解コンデンサ、４は直流チョッパ回路、５は負荷を示す。
【０００３】
図５に示した整流回路では、三相交流電源１の電圧をダイオード整流器２で全波整流し、この全波整流電圧を電解コンデンサ３で平滑された直流電圧にし、この直流電圧を直流チョッパ回路４により任意の直流電圧に変換して、負荷５に供給する。
【０００４】
図６は、この種の整流回路の第２の従来例を示す回路構成図であり、図５に示した回路構成と同一機能を有するものには同一符号を付している。
すなわち図６に示した整流回路には図５に示したダイオード整流器２に代えて、図示の如く、自己消弧形素子としてのＩＧＢＴと、ダイオードとを逆並列接続して形成されるスイッチ回路を三相ブリッジ構成に結線された自励式整流器６を備えている。
【０００５】
図６に示した整流回路では自励式整流器６により、三相交流電源１の全波整流電圧値以上に昇圧された電圧にすることが可能であり、この電圧を電解コンデンサ３で平滑された直流電圧にし、この直流電圧を直流チョッパ回路４により任意の直流電圧に変換して、負荷５に供給する。
【０００６】
【発明が解決しようとする課題】
図５に示した従来の整流回路では、▲１▼．三相交流電源１からの電流に高調波が多く含まれる、▲２▼．電力変換段数が２段となり、この整流回路の変換効率を低下させる、▲３▼．平滑のための電解コンデンサが必要であり、この電解コンデンサは磨耗寿命部品であるため、定期的な交換作業を必要とする、などの問題点を有している。
【０００７】
また、図６に示した従来の整流回路では、自励式整流器６を構成するＩＧＢＴをＰＷＭ制御することにより、三相交流電源１からの電流をほぼ正弦波状にすることが可能であるが、▲１▼．電力変換段数が２段となり、この整流回路の変換効率を低下させる、▲２▼．平滑のための電解コンデンサが必要であり、この電解コンデンサは磨耗寿命部品であるため、定期的な交換作業を必要とする、などの問題点を有している。
この発明の目的は、上記問題点を解決する整流回路を提供することにある。
【０００８】
【課題を解決するための手段】
この第１の発明の整流回路は、自己消弧形素子とダイオードとを逆並列接続して形成される第１スイッチ回路から第１２スイッチ回路までを備え、
第１スイッチ回路から第４スイッチ回路までをフルブリッジ構成に結線して第１主回路とし、第５スイッチ回路から第８スイッチ回路までをフルブリッジ構成に結線して第２主回路とし、第９スイッチ回路から第１２スイッチ回路までをフルブリッジ構成に結線して第３主回路とし、第１主回路の一方の上，下アームの中間接続点を直接または第１交流リアクトルを介して三相交流電源の第１相に接続し、第２主回路の一方の上，下アームの中間接続点を直接または第２交流リアクトルを介して前記三相交流電源の第２相に接続し、第３主回路の一方の上，下アームの中間接続点を直接または第３交流リアクトルを介して前記三相交流電源の第３相に接続し、前記第１主回路の他方の上，下アームの中間接続点と、前記第２主回路の他方の上，下アームの中間接続点と、前記第３主回路の他方の上，下アームの中間接続点とを互いに接続すると共に、この接続点を負荷の一端に接続し、第１主回路から第３主回路までの前記上アーム側接続点または下アーム側接続点を互いに接続すると共に、この接続点を前記負荷の他端に接続してなることを特徴とする。
【０００９】
また第２の発明の整流回路は、自己消弧形素子とダイオードとを逆並列接続して形成される第１スイッチ回路から第９スイッチ回路までと、第１ダイオードと、第２ダイオードと、第３ダイオードとを備え、
第１スイッチ回路から第３スイッチ回路までと、第１ダイオードとをフルブリッジ構成に結線して第１主回路とし、第４スイッチ回路から第６スイッチ回路までと、第２ダイオードとをフルブリッジ構成に結線して第２主回路とし、第７スイッチ回路から第９スイッチ回路までと、第３ダイオードとをフルブリッジ構成に結線して第３主回路とし、第１主回路の前記スイッチ回路のみの上，下アームの中間接続点を直接または第１交流リアクトルを介して三相交流電源の第１相に接続し、第２主回路の前記スイッチ回路のみの上，下アームの中間接続点を直接または第２交流リアクトルを介して前記三相交流電源の第２相に接続し、第３主回路の前記スイッチ回路のみの上，下アームの中間接続点を直接または第３交流リアクトルを介して前記三相交流電源の第３相に接続し、前記第１主回路の他方の上，下アームの中間接続点と、前記第２主回路の他方の上，下アームの中間接続点と、前記第３主回路の他方の上，下アームの中間接続点とを互いに接続すると共に、この接続点を負荷の一端に接続し、第１主回路から第３主回路までの前記上アーム側接続点または下アーム側接続点を互いに接続すると共に、この接続点を前記負荷の他端に接続してなることを特徴とする。
【００１０】
さらに第３の発明は前記第１又は第２の発明の整流回路において、前記負荷のいずれか一方の端子と前記主回路との間に、直流リアクトルを挿設したことを特徴とする。
【００１１】
この発明によれば、先述の従来の整流回路に備えていた平滑用の電解コンデンサが不要となり、また、電力変換段数も１段にでき、整流回路の変換効率を向上させる。
【００１２】
【発明の実施の形態】
図１は、この発明の第１の実施例を示す整流回路の主回路構成図であり、図５に示した従来例回路と同一機能を有するものには同一符号を付している。
すなわち図１に示した整流回路１０には、自己消弧形素子としてのＩＧＢＴ（参照符号Ｑ₁〜Ｑ₁₂）とダイオード（参照符号Ｄ₁〜Ｄ₁₂）とをそれぞれ逆並列接続して形成される１２組のスイッチ回路を、図示の如く、フルブリッジ構成に結線した第１主回路１１，第２主回路１２，第３主回路１３と、コンデンサＣ₁〜Ｃ₃と、交流リアクトルＬ₁〜Ｌ₃と、直流リアクトルＬ_Oとを備えている。
【００１３】
この整流回路１０において、図示しない制御回路により端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを任意の組み合わせでオン・オフ制御することで、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を三相交流電源１の全波整流電圧値より低い値または高い値にすることができる。
【００１４】
例えば三相交流電源１より端子Ｒ，端子Ｓ，端子Ｔそれぞれに印加される電圧Ｖ_R，Ｖ_S，Ｖ_T間にＶ_R＞Ｖ_T＞Ｖ_Sなる関係にあるときには、ＩＧＢＴＱ₃をオンすることで、端子Ｒ→Ｌ₁→Ｄ₁→Ｑ₃→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｄ₆→Ｌ₂→端子Ｓの経路で端子Ｒ−端子Ｓ間の電圧Ｖ_RSを負荷５に印加することができる。また、ＩＧＢＴＱ₃がオンの状態でＩＧＢＴＱ₁₀をオンすることで、前述の中間電位の端子Ｔに、端子Ｔ→Ｌ₃→Ｑ₁₀→Ｄ₆→Ｌ₂→端子Ｓ、または端子Ｒ→Ｌ₁→Ｄ₁→Ｑ₃→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｄ₁₀→Ｌ₃→端子Ｔの経路で電流を流すことができる。次に、ＩＧＢＴＱ₃をオフすると、Ｄ₄，Ｄ₈，Ｄ₁₂が導通して、負荷５→端子Ｎ→Ｄ₄（Ｄ₈，Ｄ₁₂）→Ｌ_O→端子Ｐ→負荷５の経路で還流モードを形成する。
【００１５】
上述のような動作を前記制御回路により、端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを適当な高周波変調されたオン・オフ期間にすることで、三相交流電源１から電流をほぼ正弦波状に制御しながら、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を、三相交流電源１の全波整流電圧値より低い値にすることができる。
【００１６】
また、三相交流電源１より端子Ｒ，端子Ｓ，端子Ｔそれぞれに印加される電圧Ｖ_R，Ｖ_S，Ｖ_T間にＶ_R＞Ｖ_T＞Ｖ_Sなる関係にあるときに、ＩＧＢＴＱ₂をオンすると、端子Ｒ→Ｌ₁→Ｑ₂→Ｄ₆→Ｌ₂→端子Ｓ、および端子Ｒ→Ｌ₁→Ｑ₂→Ｄ₁₀→Ｌ₃→端子Ｔの経路で各相の電位差に応じた電流でＬ₁，Ｌ₂，Ｌ₃を介して三相交流電源１を短絡モードにし、その結果、Ｌ₁，Ｌ₂，Ｌ₃にはエネルギーが蓄えられる。次に、ＩＧＢＴＱ₂をオフし、ＩＧＢＴＱ₃をオンさせると、端子Ｒ→Ｌ₁→Ｄ₁→Ｑ₃→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｄ₆→Ｌ₂→端子Ｓの経路、および端子Ｒ→Ｌ₁→Ｄ₁→Ｑ₃→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｄ₁₀→Ｌ₃→端子Ｔの経路でＬ₁，Ｌ₂，Ｌ₃に蓄えたエネルギーを負荷５に供給する。
【００１７】
上述のような動作を前記制御回路により、端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを適当な高周波変調されたオン・オフ期間にすることで、三相交流電源１から電流をほぼ正弦波状に制御しながら、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を、三相交流電源１の全波整流電圧値より高い値にすることができる。
【００１８】
さらに、負荷５から三相交流電源１に電力を回生したい場合は、例えば、ＩＧＢＴＱ₄，Ｑ₈，Ｑ₁₂それぞれをオンさせて、負荷５→端子Ｐ→Ｌ_O→Ｑ₄（Ｑ₈，Ｑ₁₂）→端子Ｎ→負荷５の経路でＬ_Oにエネルギーを蓄える。次に、ＩＧＢＴＱ₄，Ｑ₈，Ｑ₁₂それぞれをオフさせ、ＩＧＢＴＱ₁，Ｑ₆をオンさせると、Ｌ_Oに蓄えたエネルギーは負荷５→端子Ｐ→Ｌ_O→Ｄ₃→Ｑ₁→Ｌ₁→端子Ｒ→三相交流電源１→端子Ｓ→Ｌ₂→Ｑ₆→端子Ｎ→負荷５の経路で回生動作を行わせることができる。
【００１９】
なお、図１に示した整流回路１０において、コンデンサＣ_{1 ,}Ｃ_{2 ,}Ｃ₃それぞれは直流電圧の平滑を目的としたものではなく、第１主回路１１，第２主回路１２，第３主回路１３それぞれのスイッチング動作に伴う配線インダクタンスのエネルギーを吸収するための極小容量の無極性コンデンサである。
【００２０】
図２は、この発明の第２の実施例を示す整流回路の主回路構成図であり、図１に示した実施例回路と同一機能を有するものには同一符号を付している。
すなわち図２に示した整流回路２０には、自己消弧形素子としてのＩＧＢＴ（参照符号Ｑ₁〜Ｑ₁₂）とダイオード（参照符号Ｄ₁〜Ｄ₁₂）とをそれぞれ逆並列接続して形成される１２組のスイッチ回路を、図示の如く、フルブリッジ構成に結線した第１主回路２１，第２主回路２２，第３主回路２３と、コンデンサＣ₁〜Ｃ₃と、交流リアクトルＬ₁〜Ｌ₃と、直流リアクトルＬ_Oとを備えている。
【００２１】
この整流回路２０において、図示しない制御回路により端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを任意の組み合わせでオン・オフ制御することで、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を三相交流電源１の全波整流電圧値より低い値または高い値にすることができる。
【００２２】
例えば三相交流電源１より端子Ｒ，端子Ｓ，端子Ｔそれぞれに印加される電圧Ｖ_R，Ｖ_S，Ｖ_T間にＶ_R＞Ｖ_T＞Ｖ_Sなる関係にあるときには、ＩＧＢＴＱ₈をオンすることで、端子Ｒ→Ｌ₁→Ｄ₁→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｑ₈→Ｄ₆→Ｌ₂→端子Ｓの経路で端子Ｒ−端子Ｓ間の電圧Ｖ_RSを負荷５に印加することができる。また、ＩＧＢＴＱ₈がオンの状態でＩＧＢＴＱ₁₀，Ｑ₁₂をオンすることで、前述の中間電位の端子Ｔに、端子Ｔ→Ｌ₃→Ｑ₁₀→Ｄ₁₂→Ｑ₈→Ｄ₆→Ｌ₂→端子Ｓ、または端子Ｒ→Ｌ₁→Ｄ₁→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｑ₁₂→Ｄ₁₀→Ｌ₃→端子Ｔの経路で電流を流すことができる。次に、ＩＧＢＴＱ₈をオフすると、Ｄ₃，Ｄ₇，Ｄ₁₁が導通して、負荷５→端子Ｎ→Ｄ₃（Ｄ₇，Ｄ₁₁）→Ｌ_O→端子Ｐ→負荷５の経路で還流モードを形成する。
【００２３】
上述のような動作を前記制御回路により、端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを適当な高周波変調されたオン・オフ期間にすることで、三相交流電源１から電流をほぼ正弦波状に制御しながら、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を、三相交流電源１の全波整流電圧値より低い値にすることができる。
【００２４】
また、三相交流電源１より端子Ｒ，端子Ｓ，端子Ｔそれぞれに印加される電圧Ｖ_R，Ｖ_S，Ｖ_T間にＶ_R＞Ｖ_T＞Ｖ_Sなる関係にあるときに、ＩＧＢＴＱ₅をオンすると、端子Ｒ→Ｌ₁→Ｄ₁→Ｑ₅→Ｌ₂→端子Ｓ、および端子Ｔ→Ｌ₃→Ｄ₉→Ｑ₅→Ｌ₂→端子Ｓの経路で各相の電位差に応じた電流でＬ₁，Ｌ₂，Ｌ₃を介して三相交流電源１を短絡モードにし、その結果、Ｌ₁，Ｌ₂，Ｌ₃にはエネルギーが蓄えられる。次に、ＩＧＢＴＱ₅をオフし、ＩＧＢＴＱ₈をオンさせると、端子Ｒ→Ｌ₁→Ｄ₁→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｑ₈→Ｄ₆→Ｌ₂→端子Ｓの経路、および端子Ｔ→Ｌ₃→Ｄ₉→Ｌ_O→端子Ｐ→負荷５→端子Ｎ→Ｑ₈→Ｄ₆→Ｌ₂→端子Ｓの経路でＬ₁，Ｌ₂，Ｌ₃に蓄えたエネルギーを負荷５に供給する。
【００２５】
上述のような動作を前記制御回路により、端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₁₂それぞれを適当な高周波変調されたオン・オフ期間にすることで、三相交流電源１から電流をほぼ正弦波状に制御しながら、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を、三相交流電源１の全波整流電圧値より高い値にすることができる。
【００２６】
さらに、負荷５から三相交流電源１に電力を回生したい場合は、例えば、ＩＧＢＴＱ₃，Ｑ₇，Ｑ₁₁それぞれをオンさせて、負荷５→端子Ｐ→Ｌ_O→Ｑ₃（Ｑ₇，Ｑ₁₁）→端子Ｎ→負荷５の経路でＬ_Oにエネルギーを蓄える。次に、ＩＧＢＴＱ₃，Ｑ₇，Ｑ₁₁それぞれをオフさせ、ＩＧＢＴＱ₁，Ｑ₆をオンさせると、Ｌ_Oに蓄えたエネルギーは負荷５→端子Ｐ→Ｌ_O→Ｑ₁→Ｌ₁→端子Ｒ→三相交流電源１→端子Ｓ→Ｌ₂→Ｑ₆→Ｄ₈→端子Ｎ→負荷５の経路で回生動作を行わせることができる。
【００２７】
なお、図２に示した整流回路２０において、コンデンサＣ_{1 ,}Ｃ_{2 ,}Ｃ₃それぞれは直流電圧の平滑を目的としたものではなく、第１主回路２１，第２主回路２２，第３主回路２３それぞれのスイッチング動作に伴う配線インダクタンスのエネルギーを吸収するための極小容量の無極性コンデンサである。
【００２８】
図３は、この発明の第３の実施例を示す整流回路の主回路構成図であり、図１に示した実施例回路と同一機能を有するものには同一符号を付している。
すなわち図３に示した整流回路３０には、自己消弧形素子としてのＩＧＢＴ（参照符号Ｑ₁〜Ｑ₃，Ｑ₅〜Ｑ₇，Ｑ₉〜Ｑ₁₁）とダイオード（参照符号Ｄ₁〜Ｄ₃，Ｄ₅〜Ｄ₇，Ｄ₉〜Ｄ₁₁）とをそれぞれ逆並列接続して形成される９組のスイッチ回路と、ダイオードＤ₄と、ダイオードＤ₈と、ダイオードＤ₁₂とを、図示の如く、フルブリッジ構成に結線した第１主回路３１，第２主回路３２，第３主回路３３と、コンデンサＣ₁〜Ｃ₃と、交流リアクトルＬ₁〜Ｌ₃と、直流リアクトルＬ_Oとを備えている。
【００２９】
この整流回路３０が図１に示した整流回路１０と異なる点は、第１主回路におけるＩＧＢＴＱ₄が省略され、第２主回路におけるＩＧＢＴＱ₈が省略され、第３主回路におけるＩＧＢＴＱ₁₂が省略されていることであり、その結果、負荷５から三相交流電源１に電力を回生することができないが、この整流回路３０において、先述の整流回路１０と同様に、図示しない制御回路により端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁〜Ｑ₃，Ｑ₅〜Ｑ₇，Ｑ₉〜Ｑ₁₁それぞれを任意の組み合わせでオン・オフ制御することで、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を三相交流電源１の全波整流電圧値より低い値または高い値にすることができる。
【００３０】
なお、図３に示した整流回路３０において、コンデンサＣ_{1 ,}Ｃ_{2 ,}Ｃ₃それぞれは直流電圧の平滑を目的としたものではなく、第１主回路３１，第２主回路３２，第３主回路３３それぞれのスイッチング動作に伴う配線インダクタンスのエネルギーを吸収するための極小容量の無極性コンデンサである。
【００３１】
図４は、この発明の第４の実施例を示す整流回路の主回路構成図であり、図２に示した実施例回路と同一機能を有するものには同一符号を付している。
すなわち図４に示した整流回路３０には、自己消弧形素子としてのＩＧＢＴ（参照符号Ｑ₁，Ｑ₂，Ｑ₄，Ｑ₅，Ｑ₆，Ｑ₈，Ｑ₉，Ｑ₁₀，Ｑ₁₂）とダイオード（参照符号Ｄ₁，Ｄ₂，Ｄ₄，Ｄ₅，Ｄ₆，Ｄ₈，Ｄ₉，Ｄ₁₀，Ｄ₁₂）とをそれぞれ逆並列接続して形成される９組のスイッチ回路と、ダイオードＤ₃と、ダイオードＤ₇と、ダイオードＤ₁₁とを、図示の如く、フルブリッジ構成に結線した第１主回路４１，第２主回路４２，第３主回路４３と、コンデンサＣ₁〜Ｃ₃と、交流リアクトルＬ₁〜Ｌ₃と、直流リアクトルＬ_Oとを備えている。
【００３２】
この整流回路４０が図２に示した整流回路２０と異なる点は、第１主回路におけるＩＧＢＴＱ₃が省略され、第２主回路におけるＩＧＢＴＱ₇が省略され、第３主回路におけるＩＧＢＴＱ₁₁が省略されていることであり、その結果、負荷５から三相交流電源１に電力を回生することができないが、この整流回路３０において、先述の整流回路２０と同様に、図示しない制御回路により端子Ｒ，端子Ｓ，端子Ｔに三相交流電源１から印加される電圧の位相に応じて、ＩＧＢＴＱ₁，Ｑ₂，Ｑ₄，Ｑ₅，Ｑ₆，Ｑ₈，Ｑ₉，Ｑ₁₀，Ｑ₁₂を任意の組み合わせでオン・オフ制御することで、端子Ｐ，端子Ｎから負荷５に供給される直流電圧を三相交流電源１の全波整流電圧値より低い値または高い値にすることができる。
【００３３】
なお、図４に示した整流回路４０において、コンデンサＣ_{1 ,}Ｃ_{2 ,}Ｃ₃それぞれは直流電圧の平滑を目的としたものではなく、第１主回路４１，第２主回路４２，第３主回路４３それぞれのスイッチング動作に伴う配線インダクタンスのエネルギーを吸収するための極小容量の無極性コンデンサである。
【００３４】
【発明の効果】
この発明の整流回路によれば、従来の整流回路に備えていた定期的交換部品である平滑用の電解コンデンサが不要となり、その結果、保守点検作業が簡略化される。また、この整流回路では電力変換段数も１段にでき、該整流回路の変換効率を向上させる。
【図面の簡単な説明】
【図１】この発明の第１の実施例を示す回路構成図
【図２】この発明の第２の実施例を示す回路構成図
【図３】この発明の第３の実施例を示す回路構成図
【図４】この発明の第４の実施例を示す回路構成図
【図５】従来例を示す回路構成図
【図６】図５とは別の従来例を示す回路構成図
【符号の説明】
１…三相交流電源、２…ダイオード整流器、３…電解コンデンサ、４…直流チョッパ回路、５…負荷、６…自励式整流器、１０…整流回路、１１…第１主回路、１２…第２主回路、１３…第３主回路、２０…整流回路、２１…第１主回路、２２…第２主回路、２３…第３主回路、３０…整流回路、３１…第１主回路、３２…第２主回路、３３…第３主回路、４０…整流回路、４１…第１主回路、４２…第２主回路、４３…第３主回路、Ｑ₁〜Ｑ₁₂…ＩＧＢＴ、Ｄ₁〜Ｄ₁₂…ダイオード、Ｃ₁〜Ｃ₃…コンデンサ、Ｌ₁〜Ｌ₃…交流リアクトル、Ｌ_O…直流リアクトル。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rectifier circuit that converts a three-phase AC voltage into an arbitrary DC voltage and supplies the DC voltage to a load.
[0002]
[Prior art]
FIG. 5 is a circuit configuration diagram showing a first conventional example of this type of rectifier circuit, wherein 1 is a three-phase AC power source, 2 is a diode rectifier connected in a three-phase bridge configuration, and 3 is a smoothing electrolytic capacitor. Reference numeral 4 denotes a DC chopper circuit, and 5 denotes a load.
[0003]
In the rectifier circuit shown in FIG. 5, the voltage of the three-phase AC power source 1 is full-wave rectified by the diode rectifier 2, and this full-wave rectified voltage is converted to a DC voltage smoothed by the electrolytic capacitor 3, and this DC voltage is converted to a DC chopper circuit. 4 is converted into an arbitrary DC voltage and supplied to the load 5.
[0004]
FIG. 6 is a circuit configuration diagram showing a second conventional example of this type of rectifier circuit. Components having the same functions as those of the circuit configuration shown in FIG. 5 are denoted by the same reference numerals.
That is, instead of the diode rectifier 2 shown in FIG. 5, the rectifier circuit shown in FIG. 6 includes a switch circuit formed by connecting an IGBT as a self-extinguishing element and a diode in reverse parallel as shown in the figure. A self-excited rectifier 6 wired in a three-phase bridge configuration is provided.
[0005]
In the rectifier circuit shown in FIG. 6, the self-excited rectifier 6 can make the voltage boosted to a value equal to or higher than the full-wave rectified voltage value of the three-phase AC power supply 1, and this voltage is DC smoothed by the electrolytic capacitor 3. This DC voltage is converted into an arbitrary DC voltage by the DC chopper circuit 4 and supplied to the load 5.
[0006]
[Problems to be solved by the invention]
In the conventional rectifier circuit shown in FIG. The current from the three-phase AC power source 1 contains a lot of harmonics, (2). The number of power conversion stages becomes two, and the conversion efficiency of this rectifier circuit is lowered. (3). An electrolytic capacitor for smoothing is required, and since this electrolytic capacitor is a wear-life component, it has problems such as requiring periodic replacement work.
[0007]
Further, in the conventional rectifier circuit shown in FIG. 6, it is possible to make the current from the three-phase AC power source 1 substantially sinusoidal by PWM control of the IGBT that constitutes the self-excited rectifier 6. 1 ▼. The number of power conversion stages becomes two, and the conversion efficiency of this rectifier circuit is lowered. (2). An electrolytic capacitor for smoothing is required, and since this electrolytic capacitor is a wear-life component, it has problems such as requiring periodic replacement work.
An object of the present invention is to provide a rectifier circuit that solves the above problems.
[0008]
[Means for Solving the Problems]
The rectifier circuit according to the first invention includes a first switch circuit to a twelfth switch circuit formed by connecting a self-extinguishing element and a diode in antiparallel.
The first switch circuit to the fourth switch circuit are connected in a full bridge configuration to form a first main circuit, and the fifth switch circuit to the eighth switch circuit are connected in a full bridge configuration to form a second main circuit. The switch circuit to the twelfth switch circuit are connected in a full-bridge configuration to form the third main circuit, and the intermediate connection point of one of the upper and lower arms of the first main circuit is directly connected to the three-phase AC via the first AC reactor. Connect to the first phase of the power supply, connect the intermediate connection point of one of the upper and lower arms of the second main circuit to the second phase of the three-phase AC power supply either directly or via the second AC reactor, An intermediate connection point between the upper and lower arms of one circuit is connected to the third phase of the three-phase AC power source directly or via a third AC reactor, and an intermediate connection between the other upper and lower arms of the first main circuit. And on the other side of the second main circuit An intermediate connection point of the lower arm and an intermediate connection point of the other upper and lower arms of the third main circuit are connected to each other, and this connection point is connected to one end of the load, from the first main circuit to the third main circuit. The upper arm side connection point or the lower arm side connection point up to the circuit is connected to each other, and this connection point is connected to the other end of the load.
[0009]
A rectifier circuit according to a second aspect of the invention includes a first switch circuit to a ninth switch circuit formed by antiparallel connection of a self-extinguishing element and a diode, a first diode, a second diode, 3 diodes,
The first switch circuit to the third switch circuit and the first diode are connected in a full bridge configuration to form a first main circuit, and the fourth switch circuit to the sixth switch circuit and the second diode are configured in a full bridge configuration. To the second main circuit, the seventh switch circuit to the ninth switch circuit, and the third diode are connected in a full bridge configuration to form the third main circuit, and only the switch circuit of the first main circuit is connected. Connect the intermediate connection point of the upper and lower arms directly or through the first AC reactor to the first phase of the three-phase AC power supply, and directly connect the intermediate connection point of the upper and lower arms of the second main circuit only Alternatively, it is connected to the second phase of the three-phase AC power source via the second AC reactor, and the intermediate connection points of the upper and lower arms of only the third main circuit are connected directly or via the third AC reactor. Connected to the third phase of the three-phase AC power source, the intermediate connection point of the other upper and lower arms of the first main circuit, the intermediate connection point of the other upper and lower arms of the second main circuit, and the first The other upper and lower arm intermediate connection points of the three main circuits are connected to each other, and this connection point is connected to one end of the load, and the upper arm side connection point from the first main circuit to the third main circuit or The lower arm side connection point is connected to each other, and this connection point is connected to the other end of the load.
[0010]
Furthermore, a third invention is characterized in that in the rectifier circuit of the first or second invention, a DC reactor is inserted between any one terminal of the load and the main circuit.
[0011]
According to the present invention, the smoothing electrolytic capacitor provided in the above-described conventional rectifier circuit becomes unnecessary, the number of power conversion stages can be reduced to one, and the conversion efficiency of the rectifier circuit is improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a main circuit configuration diagram of a rectifier circuit showing a first embodiment of the present invention. Components having the same functions as those in the conventional circuit shown in FIG.
That is, the rectifier circuit 10 shown in FIG. 1 is formed by connecting IGBTs (reference symbols Q _{1 to} Q ₁₂ ) as self-extinguishing elements and diodes (reference symbols D _{1 to} D ₁₂ ) in antiparallel. As shown in the figure, the 12 main switch circuits, the first main circuit 11, the second main circuit 12, and the third main circuit 13, the capacitors C _{1 to} C _3, and the AC reactors L ₁ to L L ₃ and a DC reactor L _O are provided.
[0013]
In this rectifier circuit 10, IGBTs Q _{1 to} Q ₁₂ are turned on / off in any combination according to the phase of the voltage applied from the three-phase AC power supply 1 to the terminals R, S, and T by a control circuit (not shown). By controlling, the DC voltage supplied from the terminals P and N to the load 5 can be set to a value lower or higher than the full-wave rectified voltage value of the three-phase AC power supply 1.
[0014]
For example, when there is a relationship V _R > V _T > V _S between the voltages V _R , V _S , and V _T applied from the three-phase AC power source 1 to the terminals R, S, and T, respectively, the IGBT Q ₃ is turned on. Thus, the voltage V _RS between the terminal R and the terminal S is loaded through the path of the terminal R → L ₁ → D ₁ → Q ₃ → L _O → terminal P → load 5 → terminal N → D ₆ → L ₂ → terminal S. 5 can be applied. Further, by turning on the IGBTQ ₁₀ in IGBTQ ₃ is on, the terminal T of the intermediate potential of the above, the terminal _{_{T → L 3 → Q 10 →}} D 6 → L 2 → terminal S or the terminal R → L _1, → D ₁ → Q ₃ → L _O → terminal P → load 5 → terminal N → D ₁₀ → L ₃ → terminal T Next, when IGBTQ ₃ is turned off, D ₄ , D ₈ , and D ₁₂ are turned on, and return through a route of load 5 → terminal N → D ₄ (D ₈ , D ₁₂ ) → L _O → terminal P → load 5. Form a mode.
[0015]
According to the phase of the voltage applied from the three-phase AC power source 1 to the terminals R, S, and T by the control circuit, the above-described operations are performed on each of the IGBTs Q _{1 to} Q ₁₂ that have been appropriately high frequency modulated.・ By controlling the current from the three-phase AC power source 1 in a substantially sine wave shape by setting the off-period, the DC voltage supplied from the terminals P and N to the load 5 is changed to the full-wave rectified voltage of the three-phase AC power source 1 The value can be lower than the value.
[0016]
Further, when there is a relationship of V _R > V _T > V _S between the voltages V _R , V _S , and V _T applied from the three-phase AC power source 1 to the terminals R, S, and T, respectively, IGBTQ ₂ When turned on, the current corresponding to the potential difference of each phase in the path of terminal R → L ₁ → Q ₂ → D ₆ → L ₂ → terminal S and terminal R → L ₁ → Q ₂ → D ₁₀ → L ₃ → terminal T Thus, the three-phase AC power supply 1 is put into a short-circuit mode via L ₁ , L ₂ and L ₃ , and as a result, energy is stored in L ₁ , L ₂ and L ₃ . Next, when IGBTQ ₂ is turned off and IGBTQ ₃ is turned on, the path of terminal R → L ₁ → D ₁ → Q ₃ → L _O → terminal P → load 5 → terminal N → D ₆ → L ₂ → terminal S And the energy stored in L ₁ , L ₂ , and L ₃ in the route of terminal R → L ₁ → D ₁ → Q ₃ → L _O → terminal P → load 5 → terminal N → D ₁₀ → L ₃ → terminal T Supply to load 5.
[0017]
According to the phase of the voltage applied from the three-phase AC power source 1 to the terminals R, S, and T by the control circuit, the above-described operations are performed on each of the IGBTs Q _{1 to} Q ₁₂ that have been appropriately high frequency modulated.・ By controlling the current from the three-phase AC power source 1 in a substantially sine wave shape by setting the off-period, the DC voltage supplied from the terminals P and N to the load 5 is changed to the full-wave rectified voltage The value can be higher than the value.
[0018]
Furthermore, when it is desired to regenerate power from the load 5 to the three-phase AC power source 1, for example, the IGBTs Q ₄ , Q ₈ , and Q ₁₂ are turned on, and the load 5 → terminal P → L _O → Q ₄ (Q ₈ , Q ₁₂ ) Energy is stored in L 2 _{O through} a route of terminal N → load 5. Next, when the IGBTs Q ₄ , Q ₈ , and Q ₁₂ are turned off and the IGBTs Q ₁ and Q ₆ are turned on, the energy stored in the L _O becomes the load 5 → terminal P → L _O → D ₃ → Q ₁ → L ₁ The regenerative operation can be performed in the route of terminal R → three-phase AC power source 1 → terminal S → L ₂ → Q ₆ → terminal N → load 5.
[0019]
In the rectifier circuit 10 shown in FIG. 1, the capacitors C _1, C _{2, and} C ₃ are not intended for smoothing the DC voltage, but are the first main circuit 11, the second main circuit 12, and the third main circuit. This is a non-polar capacitor having a minimum capacity for absorbing the energy of the wiring inductance accompanying the switching operation of each circuit 13.
[0020]
FIG. 2 is a main circuit configuration diagram of a rectifier circuit showing a second embodiment of the present invention. Components having the same functions as those of the embodiment circuit shown in FIG.
That is, the rectifier circuit 20 shown in FIG. 2 is formed by connecting the IGBTs (reference symbols Q _{1 to} Q ₁₂ ) and the diodes (reference symbols D _{1 to} D ₁₂ ) as self-extinguishing elements in antiparallel. that the 12 pairs of switching circuits, as shown, the first main circuit 21 which is connected to a full bridge configuration, the second main circuit 22, the third main circuit 23, a capacitor C ₁ -C _3, AC reactors L ₁ ~ L ₃ and a DC reactor L _O are provided.
[0021]
In this rectifier circuit 20, IGBTs Q _{1 to} Q ₁₂ are turned on / off in any combination according to the phase of the voltage applied from the three-phase AC power supply 1 to the terminals R, S, and T by a control circuit (not shown). By controlling, the DC voltage supplied from the terminals P and N to the load 5 can be set to a value lower or higher than the full-wave rectified voltage value of the three-phase AC power supply 1.
[0022]
For example, when there is a relationship of V _R > V _T > V _S between the voltages V _R , V _S , and V _T applied from the three-phase AC power source 1 to the terminals R, S, and T, respectively, the IGBT Q ₈ is turned on. Thus, the voltage V _RS between the terminal R and the terminal S is loaded through the path of the terminal R → L ₁ → D ₁ → L _O → terminal P → load 5 → terminal N → Q ₈ → D ₆ → L ₂ → terminal S. 5 can be applied. Further, by turning on the IGBTs Q ₁₀ and Q ₁₂ with the IGBT Q ₈ turned on, the terminal T → L ₃ → Q ₁₀ → D ₁₂ → Q ₈ → D ₆ → L ₂ → A current can flow through the path of the terminal S or the terminal R → L ₁ → D ₁ → L _O → terminal P → load 5 → terminal N → Q ₁₂ → D ₁₀ → L ₃ → terminal T. Next, when IGBTQ ₈ is turned off, D ₃ , D ₇ , and D ₁₁ become conductive, and return through a route of load 5 → terminal N → D ₃ (D ₇ , D ₁₁ ) → L _O → terminal P → load 5. Form a mode.
[0023]
According to the phase of the voltage applied from the three-phase AC power source 1 to the terminals R, S, and T by the control circuit, the above-described operations are performed on each of the IGBTs Q _{1 to} Q ₁₂ that have been appropriately high frequency modulated.・ By controlling the current from the three-phase AC power source 1 in a substantially sine wave shape by setting the off-period, the DC voltage supplied from the terminals P and N to the load 5 is changed to the full-wave rectified voltage of the three-phase AC power source 1 The value can be lower than the value.
[0024]
Further, when there is a relationship of V _R > V _T > V _S between the voltages V _R , V _S , and V _T applied from the three-phase AC power source 1 to the terminals R, S, and T, respectively, IGBTQ ₅ When turned on, the current corresponding to the potential difference of each phase in the path of terminal R → L ₁ → D ₁ → Q ₅ → L ₂ → terminal S and terminal T → L ₃ → D ₉ → Q ₅ → L ₂ → terminal S Thus, the three-phase AC power supply 1 is put into a short-circuit mode via L ₁ , L ₂ and L ₃ , and as a result, energy is stored in L ₁ , L ₂ and L ₃ . Next, when IGBTQ ₅ is turned off and IGBTQ ₈ is turned on, the path of terminal R → L ₁ → D ₁ → L _O → terminal P → load 5 → terminal N → Q ₈ → D ₆ → L ₂ → terminal S And the energy stored in L ₁ , L ₂ , L ₃ in the path of terminal T → L ₃ → D ₉ → L _O → terminal P → load 5 → terminal N → Q ₈ → D ₆ → L ₂ → terminal S Supply to load 5.
[0025]
According to the phase of the voltage applied from the three-phase AC power source 1 to the terminals R, S, and T by the control circuit, the above-described operations are performed on each of the IGBTs Q _{1 to} Q ₁₂ that have been appropriately high frequency modulated.・ By controlling the current from the three-phase AC power source 1 in a substantially sine wave shape by setting the off-period, the DC voltage supplied from the terminals P and N to the load 5 is changed to the full-wave rectified voltage of the three-phase AC power source 1 The value can be higher than the value.
[0026]
Furthermore, when it is desired to regenerate power from the load 5 to the three-phase AC power source 1, for example, the IGBTs Q ₃ , Q ₇ , and Q ₁₁ are turned on, and the load 5 → terminal P → L _O → Q ₃ (Q ₇ , Q ₁₁ ) Store energy in L _{O through} the route of terminal N → load 5. Next, when the IGBTs Q ₃ , Q ₇ , and Q ₁₁ are turned off and the IGBTs Q ₁ and Q ₆ are turned on, the energy stored in the L _O becomes the load 5 → terminal P → L _O → Q ₁ → L ₁ → terminal R -> Three-phase AC power supply 1-> terminal S-> L _2- > Q _6- > D _8- > terminal N-> The regenerative operation can be performed in the path of load 5.
[0027]
In the rectifier circuit 20 shown in FIG. 2, the capacitors C _1, C _{2, and} C ₃ are not intended for smoothing the DC voltage, but the first main circuit 21, the second main circuit 22, and the third main circuit This is a nonpolar capacitor having a minimum capacity for absorbing the energy of the wiring inductance accompanying the switching operation of each circuit 23.
[0028]
FIG. 3 is a main circuit configuration diagram of a rectifier circuit showing a third embodiment of the present invention. Components having the same functions as those of the embodiment circuit shown in FIG.
That is, the rectifier circuit 30 shown in FIG. 3 includes IGBTs (reference symbols Q _{1 to} Q ₃ , Q _{5 to} Q ₇ , Q _{9 to} Q ₁₁ ) and diodes (reference symbols D _{1 to} D ₁₁ ) as self-extinguishing elements. ₃ , D _{5 to} D ₇ , D _{9 to} D ₁₁ ) are connected in reverse parallel to each other, and nine sets of switch circuits, a diode D ₄ , a diode D _8, and a diode D ₁₂ are illustrated. Thus, the first main circuit 31, the second main circuit 32, the third main circuit 33, the capacitors C _{1 to} C ₃ , the AC reactors L _{1 to} L _3, and the DC reactor L _O connected in a full bridge configuration I have.
[0029]
The rectifier circuit 30 is different from the rectifier circuit 10 shown in FIG. 1 in that the IGBTQ ₄ in the first main circuit is omitted, the IGBTQ ₈ in the second main circuit is omitted, and the IGBTQ ₁₂ in the third main circuit is omitted. As a result, power cannot be regenerated from the load 5 to the three-phase AC power source 1, but in the rectifier circuit 30, as in the rectifier circuit 10 described above, the terminals R, The IGBTs Q _{1 to} Q ₃ , Q _{5 to} Q ₇ , and Q _{9 to} Q ₁₁ are controlled to be turned on / off in any combination according to the phase of the voltage applied from the three-phase AC power supply 1 to the terminals S and T. Thus, the DC voltage supplied from the terminals P and N to the load 5 can be set to a value lower or higher than the full-wave rectified voltage value of the three-phase AC power supply 1.
[0030]
In the rectifier circuit 30 shown in FIG. 3, each of the capacitors C _1, C _{2, and} C ₃ is not intended to smooth DC voltage, but the first main circuit 31, the second main circuit 32, and the third main circuit This is a non-polar capacitor having a minimum capacity for absorbing the energy of the wiring inductance accompanying the switching operation of each circuit 33.
[0031]
FIG. 4 is a main circuit configuration diagram of a rectifier circuit showing a fourth embodiment of the present invention. Components having the same functions as those of the embodiment circuit shown in FIG.
That is, the rectifier circuit 30 shown in FIG. 4 includes IGBTs (reference symbols Q ₁ , Q ₂ , Q ₄ , Q ₅ , Q ₆ , Q ₈ , Q ₉ , Q ₁₀ , Q ₁₂ ) as self-extinguishing elements. And nine switch circuits formed by connecting anti-parallel diodes (reference symbols D ₁ , D ₂ , D ₄ , D ₅ , D ₆ , D ₈ , D ₉ , D ₁₀ , D ₁₂ ), respectively, A first main circuit 41, a second main circuit 42, a third main circuit 43, and capacitors C _{1 to} C, in which a diode D ₃ , a diode D ₇ and a diode D ₁₁ are connected in a full bridge configuration as shown in the figure. ₃ , AC reactors L _{1 to} L _3, and a DC reactor L _O.
[0032]
The rectifier circuit 40 is different from the rectifier circuit 20 shown in FIG. 2 in that the IGBTQ ₃ in the first main circuit is omitted, the IGBTQ ₇ in the second main circuit is omitted, and the IGBTQ ₁₁ in the third main circuit is omitted. As a result, power cannot be regenerated from the load 5 to the three-phase AC power source 1, but in the rectifier circuit 30, as in the rectifier circuit 20 described above, the terminals R, terminal S, depending on the voltage of the phase to be applied from the three-phase AC power source 1 to the terminal T, optionally _{_{_{IGBTQ 1, Q 2, Q 4}}} , Q 5, Q 6, Q 8, Q 9, Q 10, Q 12 By performing on / off control with the combination of the above, the DC voltage supplied from the terminals P and N to the load 5 can be made lower or higher than the full-wave rectified voltage value of the three-phase AC power supply 1.
[0033]
In the rectifier circuit 40 shown in FIG. 4, the capacitors C _1, C _{2, and} C ₃ are not intended for smoothing the DC voltage, but are the first main circuit 41, the second main circuit 42, and the third main circuit. This is a non-polar capacitor having a minimum capacity for absorbing the energy of the wiring inductance accompanying the switching operation of each circuit 43.
[0034]
【The invention's effect】
According to the rectifier circuit of the present invention, the electrolytic capacitor for smoothing, which is a periodic replacement part provided in the conventional rectifier circuit, becomes unnecessary, and as a result, maintenance and inspection work is simplified. Further, in this rectifier circuit, the number of power conversion stages can be made one, and the conversion efficiency of the rectifier circuit is improved.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram showing a first embodiment of the invention. FIG. 2 is a circuit configuration diagram showing a second embodiment of the invention. FIG. 3 is a circuit configuration showing a third embodiment of the invention. FIG. 4 is a circuit configuration diagram showing a fourth embodiment of the present invention. FIG. 5 is a circuit configuration diagram showing a conventional example. FIG. 6 is a circuit configuration diagram showing a conventional example different from FIG. ]
DESCRIPTION OF SYMBOLS 1 ... Three-phase alternating current power supply, 2 ... Diode rectifier, 3 ... Electrolytic capacitor, 4 ... DC chopper circuit, 5 ... Load, 6 ... Self-excited rectifier, 10 ... Rectifier circuit, 11 ... 1st main circuit, 12 ... 2nd main Circuits: 13 ... third main circuit, 20 ... rectifier circuit, 21 ... first main circuit, 22 ... second main circuit, 23 ... third main circuit, 30 ... rectifier circuit, 31 ... first main circuit, 32 ... first 2 main circuit, 33 ... third main circuit, 40 ... rectifying circuit, 41 ... first main circuit, 42 ... second main circuit, 43 ... third main _{_{circuit, Q 1 ~Q 12 ... IGBT,}} D 1 ~D 12 ... Diodes, C _{1 to} C ₃ ... Capacitors, L _{1 to} L ₃ ... AC reactors, L _O ... DC reactors.

Claims

Comprising a first switch circuit to a twelfth switch circuit formed by connecting a self-extinguishing element and a diode in reverse parallel;
The first switch circuit to the fourth switch circuit are connected in a full bridge configuration to be the first main circuit,
The fifth switch circuit to the eighth switch circuit are connected in a full bridge configuration to form a second main circuit,
The ninth switch circuit to the twelfth switch circuit are connected in a full bridge configuration to form a third main circuit,
Connect the middle connection point of the upper and lower arms of one side of the first main circuit to the first phase of the three-phase AC power source directly or via the first AC reactor,
An intermediate connection point of one of the upper and lower arms of the second main circuit is connected to the second phase of the three-phase AC power source directly or via a second AC reactor;
An intermediate connection point of one of the upper and lower arms of the third main circuit is connected to the third phase of the three-phase AC power source directly or via a third AC reactor;
An intermediate connection point between the other upper and lower arms of the first main circuit, an intermediate connection point between the other upper and lower arms of the second main circuit, and an intermediate connection point between the other upper and lower arms of the third main circuit. Connect the connection points to each other, connect this connection point to one end of the load,
A rectifier circuit characterized in that the upper arm side connection point or the lower arm side connection point from the first main circuit to the third main circuit are connected to each other and the connection point is connected to the other end of the load. .

A first switch circuit to a ninth switch circuit formed by connecting a self-extinguishing element and a diode in antiparallel, a first diode, a second diode, and a third diode;
The first switch circuit to the third switch circuit and the first diode are connected in a full bridge configuration to form a first main circuit,
From the fourth switch circuit to the sixth switch circuit and the second diode are connected in a full bridge configuration to form a second main circuit,
The seventh switch circuit to the ninth switch circuit and the third diode are connected in a full bridge configuration to form a third main circuit,
The intermediate connection point of the upper and lower arms only of the switch circuit of the first main circuit is connected to the first phase of the three-phase AC power source directly or via the first AC reactor,
An intermediate connection point of the upper and lower arms only of the switch circuit of the second main circuit is connected to the second phase of the three-phase AC power source directly or via a second AC reactor;
The intermediate connection point of the upper and lower arms only of the switch circuit of the third main circuit is connected to the third phase of the three-phase AC power source directly or via a third AC reactor,
An intermediate connection point between the other upper and lower arms of the first main circuit, an intermediate connection point between the other upper and lower arms of the second main circuit, and an intermediate connection point between the other upper and lower arms of the third main circuit. Connect the connection points to each other, connect this connection point to one end of the load,
A rectifier circuit characterized in that the upper arm side connection point or the lower arm side connection point from the first main circuit to the third main circuit are connected to each other and the connection point is connected to the other end of the load. .

The rectifier circuit according to claim 1, wherein a DC reactor is inserted between any one of the terminals of the load and the main circuit.